Title: New methods for B meson decay constants and form factors from lattice NRQCD

We determine the normalization of scalar and pseudoscalar current operators made from nonrelativistic b quarks and highly improved staggered light quarks in lattice quantum chromodynamics (QCD) through O(α s) and Λ QCD/m b. We use matrix elements of these operators to extract B meson decay constants and form factors, and then compare to those obtained using the standard vector and axial-vector operators. This provides a test of systematic errors in the lattice QCD determination of the B meson decay constants and form factors. We provide a new value for the B and B s meson decay constants from lattice QCD calculations on ensembles that include u, d, s, and c quarks in the sea and those that have the u/d quark mass going down to its physical value. Our results are f B=0.196(6) GeV, f Bs=0.236(7) GeV, and f Bs/f B=1.207(7), agreeing well with earlier results using the temporal axial current. By combining with these previous results, we provide updated values of f B=0.190(4) GeV, f Bs=0.229(5) GeV, and f Bs/f B=1.206(5).

@article{osti_1427314,
title = {New methods for B meson decay constants and form factors from lattice NRQCD},
author = {Hughes, C. and Davies, C. T.H. and Monahan, C. J.},
abstractNote = {We determine the normalization of scalar and pseudoscalar current operators made from nonrelativistic b quarks and highly improved staggered light quarks in lattice quantum chromodynamics (QCD) through O(αs) and ΛQCD/mb. We use matrix elements of these operators to extract B meson decay constants and form factors, and then compare to those obtained using the standard vector and axial-vector operators. This provides a test of systematic errors in the lattice QCD determination of the B meson decay constants and form factors. We provide a new value for the B and Bs meson decay constants from lattice QCD calculations on ensembles that include u, d, s, and c quarks in the sea and those that have the u/d quark mass going down to its physical value. Our results are fB=0.196(6) GeV, fBs=0.236(7) GeV, and fBs/fB=1.207(7), agreeing well with earlier results using the temporal axial current. By combining with these previous results, we provide updated values of fB=0.190(4) GeV, fBs=0.229(5) GeV, and fBs/fB=1.206(5).},
doi = {10.1103/PhysRevD.97.054509},
journal = {Physical Review D},
number = 5,
volume = 97,
place = {United States},
year = {2018},
month = {3}
}

We determine the normalization of scalar and pseudoscalar current operators made from nonrelativistic b quarks and highly improved staggered light quarks in lattice quantum chromodynamics (QCD) through O(α s) and Λ QCD/m b. We use matrix elements of these operators to extract B meson decay constants and form factors, and then compare to those obtained using the standard vector and axial-vector operators. This provides a test of systematic errors in the lattice QCD determination of the B meson decay constants and form factors. We provide a new value for the B and B s meson decay constants from lattice QCDmore » calculations on ensembles that include u, d, s, and c quarks in the sea and those that have the u/d quark mass going down to its physical value. Our results are f B=0.196(6) GeV, f Bs=0.236(7) GeV, and f Bs/f B=1.207(7), agreeing well with earlier results using the temporal axial current. By combining with these previous results, we provide updated values of f B=0.190(4) GeV, f Bs=0.229(5) GeV, and f Bs/f B=1.206(5).« less